In the two months between Halloween and Christmas of 1992, Watson had lost almost of all of his 150-word vocabulary along with an interest in the world.

His parents initially failed to notice the change, chalking up the subtle signs to stubbornness or fatigue or the ever-changing nature of a developing child.

By New Year's, though, the difference was both inescapable and worrisome.

The smiling, inquisitive boy who'd sung and pranced around his house in Magee now sat sullen and withdrawn. He rarely spoke. Instead of saying "juice" or "outside," Watson met his needs by tugging the nearest adult to the refrigerator or the backdoor.

Watson also stopped playing with his toys. He used to push little cars around the living room, making vroom-vroom sounds. Now he held the vehicles upside down and close to his face while silently fixating on the wheels he'd spin for hours with his tiny fingers.

By the time his pediatrician discovered fluid in his ears and recommended tubes, Watson was a different child. His parents, Pam and Donald Dollar, hoped the surgery would return him to his previous state.

"He can't hear, that's why this is happening," Pam remembers the doctor saying. "As soon as we get those tubes in, everything will be fine."

But the procedure changed nothing.

The Dollars got the dreaded diagnosis on May 17, 1993 - 10 days after his second birthday - autism - and took immediate action.

They bombarded Watson with therapy and enrolled him in Magnolia Speech School in Jackson. They enlisted the best doctors and attended the latest autism conferences. They did everything they could to loosen autism's grip, but it wouldn't let go.

Pam and Donald eventually accepted reality: The disorder had permanently severed communication in their only child and, in doing so, isolated him from the world. Watson was lost, and he wasn't coming back.

His own mother often wondered, "Is he even in there?"

That question lingered two decades, until, on Nov. 11, 2011, Watson sent a postcard from the other side.

----

Watson awoke from sleep thirsty and plodded down the hall to the kitchen, where his mother had left a half-empty water bottle on the counter. He reached for it.

Still awake and sitting nearby, Pam quickly snatched the bottle. She was sick and didn't want Watson to get her germs. He needed to get his own water instead.

Because she doubted he'd understand a verbal explanation, Pam grabbed the bottle and drank all its contents.

Watson became agitated and was headed toward a full-blown meltdown.

So Pam tried something she'd never before attempted. She grabbed her iPad and pulled up its keyboard, then typed, "Mom is sick, when someone is sick they have germs, germs can make you ..."

Watson hesitated, then grabbed his mother's hand and slowly typed the last word of her sentence: "sick."

Pam couldn't believe it. Watson not only understood, but he was able to respond - albeit slowly and while clutching her hand. Still, she wanted to see if he'd do it again.

"Mom's water had ..." she typed.

"Germs," Watson finished.

"Mom doesn't want Watson to get sick. OK?" she wrote.

"OK," Watson replied.

A simple exchange by all accounts, but for Pam it was a breakthrough. This was the first conversation she'd ever had with her now full-grown son and the first tangible evidence that he was, indeed, "in there."

She decided to press her luck.

"Is there anything else you want to tell me?" she asked out loud.

Watson grabbed her hand and typed the words she'd been waiting to hear his whole life: "I love you, Mom. Very much."

And with that, Watson cracked a door between two worlds long ago severed by autism. That door would open again and again in the months that followed, each time revealing more of the young man who'd been trapped behind it for years.

Watson, it turns out, has been watching us all along.

His mind has cataloged a lifetime of memories that he now recalls for his mother and a few others with whom he's comfortable enough to type. He remembers the way his preschool teachers physically restrained him and said he hated that school because of it.

"It was abuse," he typed.

He remembers wanting to console his second-grade classmate after her father had died, but he didn't know how. He felt sad and helpless. It still haunts him to this day.

He can name the kids who were mean to him in school, as well as those who showed him kindness.

He's also capable of complex thoughts and is keenly aware of his disorder, as evidenced by this Dec. 13, 2011, conversation between him and his mother.

Pam: "Do you understand autism?"

Watson: "Yes, I live with it."

Pam: "Yes, you do. You understand it better than anyone. Do you like autism?"

Watson: "No, it is hard to deal with. I wish I did not have it."

Pam: "I know. Me too. It has to be very hard for you."

Watson: "(I) try to really deal with my weird stuff, but it's hard because so many things to deal with."

Pam: "You are getting better, every day. We can talk like we are now, and we weren't able to do that until a month ago."

Watson: "For a long time I wanted to talk to you, and now I can. That is great."

Pam" Yes, it's wonderful. I've wanted to talk to you for years, too. And now we can, so that means you're getting better."

Watson: "Really glad."

Pam: "Me, too. Is there anything you think people need to know about autism?"

Watson: "For people (to) try to understand more. Then they will be nicer to people with autism.

Pam: "Do you remember when you got autism?"

Watson: "Yes, it was when I was 4."

Pam: "No, it was when you were 2."

Watson: "I don't remember that."

Pam: "You were talking and were very socially outgoing, and then you changed. Something happened, but we still don't know what."

Watson: "Really? What happened to me?"

Pam: "We still don't know."

----

People like Watson who have autism suffer deficits in social interaction, communication and adaptability.

Hallmark signs of the disorder include a lack of eye contact, limited or absent language, social awkwardness, repetitive behaviors like rocking or humming, and a fixation on a narrow set of interests.

An estimated one in 50 children has autism, and boys are four times more likely to get it than girls, according to the Centers for Disease Control and Prevention.

Some people with the disorder are considered high functioning and have the ability to talk and interact with the environment despite their differences. Others, like Watson, are labeled low functioning because they lack language and a means with which to connect to the world.

The disorder typically appears before a person's second birthday but most likely is present from birth, according to the latest research.

Studies by doctors at the Marcus Autism Center in Atlanta reveal subtle, yet key, differences in early infancy that disrupt the entire developmental process.

Using eye-tracking technology, researchers found infants later diagnosed with autism don't focus on the eyes when looking at a face. Instead, they look at the mouth, or they don't look at the face at all.

That's opposite of typically developing children who glean important social cues from maintaining eye contact with caregivers.

Researchers also found typical children enjoy connecting to others - the pleasure centers of their brain light up when they do. This joy motivates them to deepen their connections through communication.

Children with autism don't get pleasure from connection and thus lose their motivation to communicate.

"The question isn't 'Why aren't they using speech?' We know why; it's not rewarding to them," said Gordon Ramsay, director of the Spoken Communication Laboratory at the Marcus Autism Center. "The question is 'Why isn't it rewarding?' That's really what we don't understand."

The answer lies somewhere inside the autistic brain, where mutations in any one of about 1,000 different genes disrupt normal synaptic firing, otherwise known as neural communication.

Everything we do - from talking to walking to slicing bread - requires neurons from different parts of the brain to share information, said Larry Young, director of Emory University's Center for Translational Social Neuroscience.

When that free flow of information slows or stops, seemingly simple tasks become difficult or impossible.

Think of an orchestra. In a typical venue, you would hear each instrument playing together harmoniously. In an autistic venue, you would still hear each instrument but fail to integrate them into a coherent piece of music.

Watson's parents say their son used to hear the full orchestra, as evidenced by video footage of the toddler interacting normally with peers and having simple back-and-forth dialogs. But for whatever reason, the instruments stopped harmonizing.

Roughly one in four children with autism experience what's commonly called "regression," Ramsay said. That means they lost skills that they'd already gained. The rest simply fail to develop those skills in the first place. No one yet understands why.

Either way, those on the autism spectrum experience the world as a confusing swirl of disjointed information. Those affected most severely likely give up trying to understand it, Young said, and they retreat into themselves and their narrow set of interests.

That appears to be the case for Watson, who spent most of the past two decades physically present but socially isolated.

----

Evident during a visit with Watson in his family's living room this summer, the odd behavior of the young man obscures his inner world. While his parents chat with a reporter, Watson leans back in his recliner and stares at the ceiling while unintelligibly reciting the script of a favorite movie.

For those who have known Watson the longest, his sudden communication comes as both a shock and a long-awaited chance to ask him their most burning questions.

Chaneka Roby has been Watson's friend since first grade. She sat by him in all their elementary school classes and visited him daily when he later was placed in a separate special education room. She had always wondered whether he truly enjoyed her company or just tolerated her presence.

Roby, who now attends Hinds Community College, discovered Watson could type after reading about it on his mother's Facebook page. She got excited, and it wasn't long before she found herself engaged in her own conversation with her childhood friend.

They swapped stories and shared memories. They also solved at least one mystery.

"I asked him why he bit my finger on the playground when we were in first grade," Roby said. "I had always wondered about that. Why did he do it?"

It turns out Watson had been frustrated by Roby's relentless urging that he go down the slide before he was ready. Eventually, he'd had enough of her prodding and bit her.

"To me, it's amazing he can type a sentence," Roby said. "It's a mystery and a blessing. I wish we would have had this technology in junior high and high school."

The first iPad hit the markets in April 2010. But while the device indeed boasts a handy keypad, typing itself has been around for decades.

So why didn't Watson communicate on a computer or typewriter years ago?

And, furthermore, why can he type his thoughts but not speak them?

Once again, the answer lies within the brain.

Remember that disjointed orchestra?

The one where each instrument plays but can't harmonize together?

It's the same concept preventing Watson from meaningful speech.

The brain requires little coordination to emit a sound, to echo a word, or to recite from memory a script. "That's like a short loop within one brain area," Young said.

To arrange thoughts in a coherent structure and articulate them vocally requires a vast network of neurons to fire simultaneously.

Watson has the thoughts in one part of his brain, grammar in another and vocal ability and muscle movements in yet another. But none of them works together.

"It's a miracle all these things can come together efficiently and timely to allow us to do all the things we can do as typical people," Young said. "But if there's a disruption in our genes that slows or impedes communication between neurons, you can throw the whole thing off in some way."

Typing still requires some coordination, but not as much as talking or writing.

Watson needs only one finger and the sleek surface of an iPad to compose his thoughts.

Even then, he struggles. Watson initially found it easier to grab his mom's hand and guide her outstretched finger to type words rather than extend his own. He doesn't do that much anymore but still prefers to clutch her hand while he types with his own finger.

"Not understand how hard it is for me to really type," he wrote.

That could explain why Watson never sought out a typewriter or computer at an early age. It's also likely why he never initiates communication now. Someone else, usually his mother, always starts the dialog. Always.

Another reason involves the social impairment common among people with autism. Even those who can readily communicate often choose not to, said Alice Shillingsburg, director of the Marcus Autism Center's Language and Learning Clinic.

"I work with kids who speak in full sentences but never ask you personal questions," Shillingsburg said. "They never ask what your favorite cartoon is. That tends to be what stands out."

----

Watson spends his days at home with his father while Pam heads the nonprofit Mississippi Parent Training and Information Center in Jackson.

The family lives on some 40 acres just east of Magee, where Watson and Don tend the yard, pick blueberries and go fishing.

The two are close despite their lack of communication. Like many sons, Watson doesn't express himself as freely with his father as he does with his mother.

"We've tried," Don said, referring to the iPad discussions. "It just doesn't work with us."

On a sunny morning in late June, the guys stroll from the house to a nearby blueberry bush. Don silently gathers the ripe fruit as Watson watches. When his father has a big handful, Watson leans his head back and opens his mouth like a baby bird. Don feeds him.

They do this several more times, until Watson has his fill, and stroll on.

When it gets too hot, father and son retreat into the one-story house where Watson grew up. Now towering over his parents at 6 feet, 3 inches, the young man disappears down the narrow hall and into his tiny bedroom.

A vast collection of Dr. Seuss books fills a floor-to-ceiling shelf and spills out into a waist-high pile near the door. Watson selects one of them and returns to the living room to watch cartoons in his recliner.

It's a leisurely lifestyle, but one that bores the 22-year-old. While most of his peers, like Roby, are in college or working, Watson is stuck at home.

"(It's) killing me to be by myself," he types.

He's lonely. He wants friends who understand him, and a job - as a "data entry person."

His parents want that for him, too, and for the first time since his autism they feel it might be possible. But it will take time and patience, and he may never achieve full independence.

Nevertheless, life for Watson and his family has improved since he started communicating.

When Watson's grandfather, Buddy Dollar, died in September, the family used the iPad to work through the grieving process. The young man had questions about death that likely would otherwise have gone unanswered.

His parents also recently discovered Watson's belief in God and his desire to be baptized.

Pam recalled a recent car ride during which Watson became agitated in the backseat, rocking violently and making noises. She previously had no way of deciphering his behavior. Now she can pull over and get the iPad.

"What's wrong?" she typed on this particular occasion.

"I want to go to Wal-Mart," Watson replied. "You just passed it."

Pam laughed at the memory before turning pensive. How many temper tantrums could have been avoided, she wondered, if they'd been able to communicate all along.

All the misunderstandings, all the guessing games, all the grief.

"He's had a history of having a lot of behavioral problems," Pam explained.

They got him into frequent trouble at school and landed him at Millcreek, a center for emotionally disturbed children.

Watson attended the psychiatric day program there for four years as an adolescent.

"It was the typical teenage rebellion," Pam said, "but he couldn't talk back, so he used his behavior."

Watson's breakthrough has raised a flurry of what-ifs, but it also has validated his parents' decision to educate him despite his outward limitations. Years of schooling taught him how to both read and spell - two skills now vital to his communication.

If the Dollars have learned anything from this experience, Pam and Donald say, it's to never limit someone's potential.

"Presume competence," Pam said. "Presume they're absorbing everything. Expose them to the world, and never give up. He was 20 years old when his big breakthrough came. It can happen."